Case report: Successive ipsilateral and contralateral laryngeal nerve palsy as probable manifestation of neuroborreliosis.

Neuroborreliosis is part of advanced stage of Lyme disease and often characterized by damage to the cranial and/or peripheral nerves. Involvement of one or both recurrent nerves is rare. Diagnosis is often difficult and based on a set of clinical manifestations, biological arguments, and cerebrospinal fluid (CSF) analysis. A 70-year-old man was referred to our Voice Clinic with a 3-month history of dysphonia caused by right vocal fold paralysis (VFP) without any cutaneous symptoms of tick bite or erythema migrans in the previous weeks and normal initial radiological examination (neck and thorax CT). Methylprednisolone had already been prescribed but without any clinical improvement. Late biological investigation 3 months after initial symptoms of VFP showed high IgG (93 U/mL; reference <10 U/mL) against (BB), which was confirmed by two immunoblot markers (VIsE, p39 antigens). Therefore, a possible manifestation of Lyme disease with involvement of the right inferior laryngeal nerve was suspected, namely Lyme neuroborreliosis. However, given the spontaneous recovery of the patient after 7 months without any adapted antimicrobial regimen treatment, the diagnosis of neuroborreliosis was not confirmed by a lumbar puncture. Nineteen months later, the patient presented again for the same symptomatology but as left VFP. High IgG (68 U/mL) and IgM (>6, reference <0.90) levels against BB were confirmed by immunoblot. Subsequently, lumbar puncture was performed and revealed IgG against BB at 46.1 UA/mL (reference<5.5 UA/mL) in the CSF, with an extremely high IgG intrathecal synthesis antibody index (281.33, positive if > 1.5). Intrathecal antibody synthesis is the gold standard for Lyme neuroborreliosis demonstrating a specific immune response to BB in the central nervous system, but with the limitation of persistence for years after eradication. Our patient did not exhibit pleocytosis in the CSF. Therefore, two criteria of the European Federation of Neurological Societies (EFNS) guidelines are fulfilled for possible neuroborreliosis. Doxycycline treatment led to rapid recovery in less than 8 weeks and normal mobility of the left vocal fold. Because of this very uncommon clinical presentation with two successive episodes of VFP for no other obvious reason and serological evidence from the serum and CSF during the second episode, we consider it possible that the first episode of VFP could also have been a manifestation of neuroborreliosis. This case is the first report of possible relapse of laryngeal palsy successively on the right, and then the left side as a manifestation of Lyme neuroborreliosis.